On the theory of aromatic substitution: IV. The orienting influence of substituents in naphthalene derivatives

Abstract The method previously described 2 ) for estimating the “inductive” effect 3 ) of substituents is applied to electrophilic substitution reactions of naphthalene derivatives. It is shown that a + I‐substituent 4 ) either at carbon atom 1 or 2 directs the entering substituent mainly to the 5‐position; the positions 8 and 4 possess a smaller reactivity. A ‐ I‐substituent at carbon atom 1 directs to the positions 4 and 8, whereas a ‐ I‐substituent at carbon atom 2 orients mainly to the 1‐position. These rules are in accordance with the available experimental data. The theory is applied more extensively to the substitution reactions of the mono‐, di‐ and tri‐nitronaphthalenes; the agreement with the experimental data is very satisfactory.